title: Establishment and characterization of porcine colonic epithelial cells grown in primary culture.
abstract: BACKGROUND
  Primary cultures of epithelial cells are suitable models for studying epithelial function and, in particular, the regulation of epithelial tightness in vitro. The aim of our study was to develop a protocol for the isolation and culture of porcine colonic epithelial cells and to establish transepithelial electrical resistance (TEER) as a functional parameter for epithelial tightness.
  
  
  METHODS
  Epithelial cells were obtained from the proximal colon of piglets by enzymatic dispase digestion. Cells were cultured on collagen-coated membrane supports for 21 days. The epithelial origin of the cells was shown by immunohistochemical detection of cytokeratin and zonula occludens protein 1 (ZO-1). Scanning electron microscopy, transmission electron microscopy and confocal microscopy were used for further morphological characterization. The integrity and tightness of the artificial epithelium were determined by measuring TEER.
  
  
  RESULTS
  The cultured epithelial cells were immunoreactive for cytokeratin and ZO-1. They showed dense microvilli on their apical membranes and expression of Na(+)/K(+)-ATPase on their basolateral membranes. Adjacent cells were connected by tight junctions. We observed TEER to continuously increase up to 870 ± 38 Ω·cm(2) during the culture period. TEER correlated with the amount of epithelial cells expressing ZO-1.
  
  
  CONCLUSIONS
  The properties of primary cultured epithelial cells resemble the structural properties of polarized colonic epithelium in vivo. Measurement of TEER seems to be suitable for studying epithelial tightness in vitro. We suggest that these primary epithelial cultures be used to investigate the regulation of the epithelial barrier function.
authors.affiliation: Institute of Veterinary Physiology, Faculty of Veterinary Medicine, Leipzig University, Leipzig, Germany.
authors.forename: Carola
authors.initials: C
authors.lastname: Petto
authors.forename: Szilvia
authors.initials: S
authors.lastname: Lesko
authors.forename: Gotthold
authors.initials: G
authors.lastname: Gäbel
authors.forename: Martina
authors.initials: M
authors.lastname: Böttner
authors.forename: Thilo
authors.initials: T
authors.lastname: Wedel
authors.forename: Johannes
authors.initials: J
authors.lastname: Kacza
authors.forename: Helga
authors.initials: H
authors.lastname: Pfannkuche
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D003106:Colon / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010750:Phosphoproteins / Q000378:metabolism; D013552:Swine; D062826:Zonula Occludens-1 Protein
chemical_list: D008565:Membrane Proteins; D010750:Phosphoproteins; D062826:Zonula Occludens-1 Protein; D007633:Keratins